HIGH AND LOW SPEED DAMPING
Since the 2006 Yamaha YZF-R6 introduced the motorcycle world to high and low speed damping, there has been a fair degree of confusion over what it actually is. Technically, it is better calling it ‘ fast and slow’ damping rather than ‘high and low speed’ and is best thought of as the speed the oil is moving around the suspension system. High speed damping refers to a sudden and fast force being applied to the suspension such as when you hit a pot hole while low speed is a more progressive and smooth movement of the suspension. Within a suspension system the damping is controlled via oil flow through small tubes and also shims on the piston. Low speed damping is adjusted via a needle in the tube varying the oil’s flow while high speed is altered via either pressure on a spring on the top of the shim stack (it is the high-speed forces opening these shims very quickly that you are trying to control) or a separate high speed shim stack system with its own bleed valve.
Swedish knobs on Öhlins TTX36